Caldiovascular diseases are increased along with the change of dietary habits and the increase of advanced ages. Almost fifty percent of these diseases may be caused by thrombus.
Platelets in plasma are mainly associated with the formation of thrombus in organisms. For the purpose of the treatment and prophylaxis of thrombotic diseases in clinical practice, there have been used a medicine which suppresses the functions of platelet or inhibits the aggregation of platelets, for example, aspirin which inhibits cyclooxygenase and ticlopidine which activates adenylcyclase.
In recent years, glycoproteins on platelet membrane have been progressively analyzed. As the results, it has been elucidated that the glycoprotein called GPIIb/IIIa is a receptor of fibrinogen. This has therefore led to the expectation that a GPIIb/IIIa antagonists would become an inhibitor of platelet aggregation having a novel action mechanism effectively used for the treatment and prophylaxis of the thrombotic diseases (Trends in Pharmacological Science, 13, 413, 1992). The compounds as the GPIIb/IIIa antagonist include a monoclonal antibody (Ann. New York Acad. Sci., 614, 193, 1991), a tripeptide derivative comprising arginine-glycine-aspartic acid (J. Med. Chem., 35, 2040, 1992), amidinophenyl derivative (J. Med. Chem., 35, 4393, 1992; Japanese Patent Laid-Open Publication Nos. 264068/1992 and 334351/1992), and a tyrosine derivative (J. Med. Chem., 35, 4640, 1992).
It is also desired to be developed a medicine having no side effects such as hemorrhage and a highly selective function as a therapeutic or prophylactic agent of thrombotic diseases.